The disclosures referred to herein to illustrate the background of the invention and to provide additional detail with respect to its practice are incorporated herein by reference and, for convenience, are referenced in the following text and respectively grouped in the appended bibliography.
Inflammatory agents are produced by a wide variety of body cells and are natural proteins produced by the cells of the immune system of most vertebrates in response to challenges by foreign agents such as viruses, bacteria, parasites, and tumor cells (1).
Cytokines are a group of proteins and peptides that are used in organisms as signaling compounds and are used to allow one cell to communicate with another. The cytokine family consists mainly of smaller water-soluble proteins and glycoproteins. Cytokines are released by many types of cells, principally activated lymphocytes, and macrophages but also endothelium, epithelium and connective tissue. They are particularly important in both innate and adaptive immune responses. Due to their central role in the immune system, cytokines are involved in a variety of immunological, inflammatory and infectious diseases.
Interleukins (ILs) are a group of inflammatory cytokines that were first seen to be expressed by white blood cells. Interleukins are produced by a wide variety of bodily cells including endothelial cells and macrophages. The family of interleukins includes IL-1 to IL-33. The function of the immune system depends in a large part on interleukins, and rare deficiencies of a number of them have been described, all featuring autoimmune diseases or immune deficiency.
Interferons (IFNs) belong to a large class of glycoproteins and are cytokines. Interferons are natural proteins produced by the cells of the immune system of most vertebrates in response to challenges by foreign agents such as viruses, bacteria, parasites and tumor cells. Interferons assist the immune response by inhibiting viral replication within other cells of the body.
Tumor necrosis factor (TNF) is a cytokine involved in systemic inflammation and is a member of a group of cytokines that all stimulate the acute phase reaction. Tumor necrosis factor causes apoptotic cell death, cellular proliferation, differentiation, inflammation, tumorigenesis, and viral replication. Tumor necrosis factor's primary role is in the regulation of immune cells. Dysregulation and, in particular, overproduction of tumor necrosis factor have been implicated in a variety of human diseases, as well as cancer
Chemokines are a family of small cytokines, or proteins that are classified according to shared structural characteristics such as small size (they are all approximately 8-10 kilo Daltons in size), and the presence of four cysteine residues in conserved locations that are key to forming their 3-dimensional shape. Chemokines have the ability to induce directed chemotaxis in nearby responsive cells (chemotactic cytokines). Some chemokines are considered pro-inflammatory and can be induced during an immune response to promote cells of the immune system to a site of infection, while others are considered homeostatic and are involved in controlling the migration of cells during normal processes of tissue maintenance or development. Chemokines exert their biological effects by interacting with G protein-linked transmembrane receptors called chemokine receptors that are selectively found on the surfaces of their target cells.
Cytokines and chemokines have the ability to stimulate leukocyte movement and play an important role in inflammation. Cytokines can influence the synthesis of other cytokines and chemokines. Cytokines can also stimulate cell proliferation acting as growth factors. Cytokines that regulate lymphocyte activation, growth and differentiation include IL-2, IL-4, IL-10, and TNF-β. Cytokines involved with natural immunity, inflammation, include TNF-α, IL-1, INF-α, INF-β, and IL-6. Cytokines that activate inflammatory cells like macrophages include IFN-γ, TNF-α, TNF-β, IL-5, IL-10, IL-12, and IL-8. Cytokines that stimulate hemopoiesis and mediate immature leukocyte growth and differentiation include IL-3, IL-7, c-kit ligand, granulocyte-macrophage, granulocyte colony-stimulating factor (G-CSF), and stem cell factor. Granulocyte colony-stimulating factor is a glycoprotein, growth factor or cytokine produced by a number of different tissues to stimulate the bone marrow to produce granulocytes and stem cells. Granulocyte colony-stimulating factor then stimulates the bone marrow to pulse them out of the marrow into the blood.
IL-8 is responsible in attracting white blood cells to the site of infection. The major cytokines that mediate inflammation are IL-1, IL-8, and TNF (α and β). IL-1 and TNF-α are produced by activated macrophages. Their secretion can be stimulated by infections, endotoxins, immune complexes, toxins, physical injury, and a variety of inflammatory processes. Their most important actions in inflammation are their effect on endothelium, leukocytes, and fibroblasts and induction of the systemic acute phase reactions. TNF also cause aggregation and priming of neutrophils, leading to a release of proteolytic enzymes, thus contributing to tissue damage. TNF-α, IL-1, and IL-6 also induce the systemic acute phase responses associated with infection, or injury, including fever, loss of appetite, the production of slow wave sleep, release of neutrophils into circulation, release of hormones, hemodynamic effects of septic shock, hypotension, decrease in vascular resistance, increased heart rate, and decrease in blood pH.
An excess of inflammatory agents can increase the production of oxygen radicals, including superoxide anions and hydrogen peroxide, produced during the inflammatory phase of an injury, which will destroy healthy tissue surrounding the site and will mitigate the positive bronchodilation effect of nitric oxide (26). Oxygen radicals can also initiate lipid peroxidation employing arachidonic acid as a substrate producing prostaglandins and leukotrienes. Hydrogen peroxide (H2O2) can induce arachidonic acid metabolism in alveolar macrophages (17, 26). Oxygen radicals also produce 8-isoprostanes, which are potent renal and pulmonary artery vasoconstrictors, bronchoconstrictors, and induce airflow obstructions (26, 27). Because oxygen radicals contribute to the instability of nitric oxide, the addition of superoxide dismutase (SOD) or catalase (15) or Vitamin E (28) protect nitric oxide to produce its desired bronchodilation (2). Hydrogen peroxide is elevated in patients with chronic obstructive pulmonary disease (COPD), asthma, and Acute Respiratory Distress Syndrome (ARDS) (26). A study in 28 patients showed a significant correlation between oxygen radical generation in white blood cell count (WBC) and the degree of bronchial hyperreactivity in vivo in nonallergic patients (18). Thus the ability of pyruvate to regulate inflammation, and inflammatory agents, which can increase the synthesis of oxygen radicals, should reduce the production of oxygen radicals when needed.
Sodium pyruvate is an antioxidant that reacts directly with oxygen radicals to neutralize them. In macrophages, and other cell lines, sodium pyruvate regulates the level of oxygen radicals by acting as an antioxidant and also increases the synthesis of nitric oxide (9). It can specifically lower the overproduction of superoxide anions. Sodium pyruvate also increases cellular levels of glutathione, a major cellular antioxidant (12). It was recently discovered that glutathione is reduced dramatically in antigen-induced asthmatic patients (13) and inhaled glutathione does not readily enter cells. Pyruvate does enter all cells via a transport system and can also cross the blood brain barrier. Excess sodium pyruvate beyond that needed to neutralize oxygen radicals will enter the bronchial and lung cells. All cells have a transport system that allow cells to concentrate pyruvate at higher concentrations than serum levels. In the cell, pyruvate raises the pH level, increases levels of ATP, decreasing levels of ADP and cAMP, and increases levels of GTP, while decreasing levels of cGMP. Nitric oxide (NO) acts in the opposite mode by increasing levels of cGMP and ADP, and requires an acidic pH range in which to work (19). While the above therapeutic compositions and methods are reported to inhibit the production of reactive oxygen intermediates, like hydrogen peroxide or peroxynitrite, none of the disclosures describe methods for treating a pulmonary disease state in mammals by regulating indigenous in vivo levels of inflammatory agents in mammalian cells.
U.S. Pat. No. 6,063,407 (Zapol et al.) discloses methods of treating, inhibiting or preventing vascular thrombosis or arterial restenosis in a mammal. The methods include causing the mammal to inhale a therapeutically effective concentration of gaseous nitric oxide. The inhaled nitric oxide may further comprise compounds that potentiate the beneficial effects of inhaled nitric oxide and antithrombotic agents that complement or supplement the beneficial effects of inhaled nitric oxide.
U.S. Pat. No. 6,020,308 (Dewhirst et al.) discloses the use of an inhibitor of nitric oxide activity, such as a nitric oxide scavenger or a nitric oxide synthase inhibitor, as an adjunct to treatment of inappropriate tissue vascularization disorders.
U.S. Pat. No. 5,891,459 (Cooke et al.) discloses the maintenance or improvement of vascular function and structure by long term administration of physiologically acceptable compounds, such as L-arginine, L-lysine, physiologically acceptable salts thereof, and polypeptide precursors thereof, which enhance the level of endogenous nitric oxide or other intermediates in the nitric oxide induced relaxation pathway in the host. The method further comprises the administration of other compounds, such as B6, folate, B12, or an antioxidant, which provide for short-term enhancement of nitric oxide.
U.S. Pat. No. 5,873,359 (Zapol et al.) discloses a method for treating or preventing bronchoconstriction or reversible pulmonary vasoconstriction in a mammal, which method includes causing the mammal to inhale a therapeutically effective concentration of gaseous nitric oxide or a therapeutically effective amount of a nitric oxide releasing compound and an inhaler device containing nitric oxide gas and/or a nitric oxide releasing compound.
U.S. Pat. No. 5,767,160 (Kaesemeyer) discloses a therapeutic mixture comprising L-arginine and an agonist of nitric oxide synthase, such as nitroglycerin for the treatment of diseases related to vasoconstriction. The vasoconstriction is relieved by stimulating the constitutive form of nitric oxide synthase (cNOS) to produce native nitric oxide. The native nitric oxide has superior beneficial effect when compared to exogenous nitric oxide produced by a L-arginine independent pathway in terms of the ability to reduce clinical endpoints and mortality.
U.S. Pat. No. 5,543,430 (Kaesemeyer) discloses a therapeutic mixture comprising a mixture of L-arginine and an agonist of nitric oxide synthase such as nitroglycerin for the treatment of diseases related to vasoconstriction. The vasoconstriction is relieved by stimulating the constitutive form of nitric oxide synthase to produce native nitric oxide. The native nitric oxide has superior beneficial effect when compared to exogenous nitric oxide produced by a L-arginine independent pathway in terms of the ability to reduce clinical endpoints and mortality.
U.S. Pat. No. 5,428,070 (Cooke et al.) discloses a method for treating atherogenesis and restenosis by long-term administration of physiologically acceptable compounds, which enhance the level of endogenous nitric oxide in the host. Alternatively, or in combination, other compounds may be administered which provide for short-term enhancement of nitric oxide, either directly or by physiological processes. In addition, cells may be genetically engineered to provide a component in the synthetic pathway to nitric oxide, so as drive the process to enhance nitric oxide concentration, particularly in conjunction with the administration of a nitric oxide precursor.
U.S. Pat. No. 5,286,739 (Kilbourn et al.) discloses an anti-hypotensive formulation comprising a mixture of amino acids, which is essentially arginine free or low in arginine (less than about 0.1%, most preferably, about 0.01%). The formulation may include ornithine, citrulline, or both. A method for prophylaxis and treatment of systemic hypotension in an animal is also provided. A method for treating hypotension caused by nitric oxide synthesis through administering a low or essentially arginine free parenteral formulation to an animal, so as to reduce or eliminate nitric oxide synthesis is described. A method for treating an animal in septic shock is also disclosed, comprising administering to the animal an anti-hypotensive formulation comprising a mixture of amino acids, which is essentially arginine free. Prophylaxis or treatment of systemic hypotension, particularly that hypotension incident to chemotherapeutic treatment with biologic response modifiers, such as tumor necrosis factor or interleukin-1 or 2, may be accomplished through the administration of the defined anti-hypotensive formulations until physiologically acceptable systolic blood pressure levels are achieved in the animal. Treatment of an animal for septic shock induced by endotoxin may also be accomplished by administering to the animal the arginine free formulations.
U.S. Pat. No. 5,217,997 (Levere et al.) discloses a method for treating a high vascular resistance disorder in a mammal by administering to a mammalian organism in need of such treatment a sufficient amount of L-arginine or pharmaceutically acceptable salt thereof to treat a high vascular resistance disorder. The L-arginine is typically administered in the range of about 1 mg to 1500 mg per day. High vascular resistance disorders include hypertension, primary or secondary vasospasm, angina pectoris, cerebral ischemia and preeclampsia. Also disclosed is a method for preventing or treating bronchial asthma in a mammal by administering to a mammalian organism in need of such prevention or treatment a sufficient amount of L-arginine to prevent or treat bronchial asthma.
U.S. Pat. No. 5,158,883 (Griffith) discloses pharmaceutically pure physiologically active NG-aminoarginine (i.e., the L or D, L form), or pharmaceutically acceptable salts thereof, administered in a nitric oxide synthesis inhibiting amount to a subject in need of such inhibition (e.g., a subject with low blood pressure or needing immunosuppressive effect) or added to a medium containing isolated organs, intact cells, cell homogenates or tissue homogenates in an amount sufficient to inhibit nitric oxide formation to elucide or control the biosynthesis, metabolism or physiological role of nitric oxide.
U.S. Pat. Nos. 5,798,388, 5,939,459, and 5,952,384 (Katz) pertain to methods for treating various disease states in mammals caused by mammalian cells involved in the inflammatory response and compositions useful in the method. The method comprises contacting the mammalian cells participating in the inflammatory response with an inflammatory mediator. The inflammatory mediator is present in an amount capable of reducing the undesired inflammatory response and is an antioxidant. The preferred inflammatory mediator is a pyruvate. Katz discloses the treatment of airway diseases of the lungs such as bronchial asthma, acute bronchitis, emphysema, chronic obstructive emphysema, centrilobular emphysema, panacinar emphysema, chronic obstructive bronchitis, reactive airway disease, cystic fibrosis, bronchiectasis, acquired bronchiectasis, kartaagener's syndrome; atelectasis, acute atelectasis, chronic atelectasis, pneumonia, essential thrombocytopenia, legionnaires disease, psittacosis, fibrogenic dust disease, diseases due to organic dust, diseases due to irritant gases and chemicals, hypersensitivity diseases of the lung, idiopathic infiltrative diseases of the lungs and the like by inhaling pyruvate containing compositions.
U.S. Pat. No. 5,296,370 (Martin et al.) discloses therapeutic compositions for preventing and reducing injury to mammalian cells and increasing the resuscitation rate of injured mammalian cells. The therapeutic composition comprises (a) pyruvate selected from the group consisting of pyruvic acid, pharmaceutically acceptable salts of pyruvic acid, and mixtures thereof, (b) an antioxidant, and (c) a mixture of saturated and unsaturated fatty acids wherein the fatty acids are those fatty acids required for the resuscitation of injured mammalian cells.
U.S. Pat. No. 6,689,810 (Martin) discloses a therapeutic composition for treating pulmonary diseases states in mammals by altering indigenous in vivo levels of nitric oxide. The therapeutic composition consists of pyruvates, pyruvate precursors, α-keto acids having four or more carbon atoms, precursors of α-keto acids having four or more carbons, and the salts thereof.
U.S. Pat. No. 7,122,578 (Martin) discloses a therapeutic composition for treating topical diseases states and injuries in mammals involving injuries, which cause pain, erythema, swelling, crusting, ischemia, scarring, and excess white blood cell infiltration. The method involves the use of α-keto acids to suppress inflammation.
WO 2006/086643 (Martin) discloses a non-pulmonary treatment of mammalian diseases and injuries caused by the over-expression of peroxynitrite.
While the above therapeutic compositions and methods are reported to inhibit the production of reactive oxygen intermediates, such as hydrogen peroxide, peroxynitrite or nitric oxide, none of the disclosures describe a method for treating a pulmonary disease state in mammals by altering indigenous in vivo levels of inflammatory agents.